One-step fabrication in aqueous solution of a granular alginate-based hydrogel for fast and efficient removal of heavy metal ions
One-step fabrication in aqueous solution of a granular alginate-based hydrogel for fast and efficient removal of heavy metal ions
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DOI：
10.1007/s10965-013-0101-0
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发表时间：
2013-02
影响因子：
2.8
通讯作者：
Wenbo Wang;Yuru Kang;Aiqin Wang
中科院分区：
文献类型：
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作者：
Wenbo Wang;Yuru Kang;Aiqin Wang
通过海藻酸钠（SA）、丙烯酸（AA）、聚乙烯吡咯烷酮（PVP）和明胶（GE）之间的接枝和交联反应，在水溶液中原位制备了粒状海藻酸盐基水凝胶。傅立叶变换红外光谱，元素分析和扫描电镜显示，AA单体接枝到SA骨干，和PVP和GE存在于水凝胶网络作为线性互穿组件。SA和AA之间的接枝聚合和交联反应产生了本体凝胶，但PVP和GE的引入到反应混合物中导致颗粒状产物的形成。SA、PAA、PVP和GE之间的静电和氢键相互作用是颗粒状产物形成的主要驱动力。吸附等温线和吸附动力学进行了评价的模型重金属离子的吸附的水凝胶之一。结果表明，该水凝胶对Ni 2+、Cu 2+、Zn 2+、Cd 2+的吸附容量分别为3.028 mmol/g、3.146 mmol/g、2.911 mmol/g、2.862 mmol/g，且对目标金属离子具有较好的吸附速率和回收能力。竞争吸附实验结果表明，该水凝胶对Cu ~（2+）的吸附能力强于其他离子。
Granular alginate-based hydrogels were prepared in situ in an aqueous solution via grafting and crosslinking reactions among sodium alginate (SA), acrylic acid (AA), polyvinylpyrrolidone (PVP), and gelatin (GE). Fourier transform infrared spectra, elemental analysis, and scanning electrical microscopy revealed that AA monomers were grafted onto an SA backbone, and that PVP and GE were present in the hydrogel network as linear interpenetrating components. The grafting polymerization and crosslinking reaction between only SA and AA yielded a bulk gel, but the introduction of PVP and GE into the reaction mixture led to the formation of granular products. Electrostatic and hydrogen-bonding interactions among SA, PAA, PVP, and GE were the main driving forces for the formation of granular products. The adsorption isotherms and adsorption kinetics were evaluated for the adsorption of model heavy-metal ions on one of the hydrogels. The results indicated that the hydrogel has satisfactory adsorption capacities (3.028 mmol/g, Ni2+; 3.146 mmol/g, Cu2+; 2.911 mmol/g, Zn2+; 2.862 mmol/g, Cd2+), adsorption rates, and recovery capacities for the target metal ions. In addition, competitive adsorption results suggested that the hydrogel has a stronger affinity for Cu2+ion than for the other ions.